- Copyright © 2017, Environmental & Engineering Geoscience
Rock mass fractures negatively affect the production of ornamental stones quarries. Fractures cause natural rock blocks which threaten extracting the required commercial block size of ornamental stones. Accurate subsurface detection and modeling of fractures is required for pre-exploitation evaluation and planning. This paper introduces a new three-dimensional deterministic fractures modeling approach using Ground Penetrating Radar (GPR) as in-situ data acquisition tool. A case study was performed in a fractured bench of a sandstone quarry in Firenzuola, Italy, using 400 MHz GPR antenna. To accurately detect fractures at true depth, an in-situ calibration based on knowing the depth of a subsurface reflector, as a reference, allowed estimating a bulk dielectric constant of the rock mass in the time of data acquisition. A data interpretation tracing technique was developed to model fractures as 3D surfaces, in two forms either irregular or planes. The modeled fractures were visualized by a multiplatform visualization software package (ParaView). A comparison between orientations of fractures measured by the traditional manual survey and orientations of the modeled fractures is presented as a possible geologic validation for the fractures detection and interpretation. For the objective of pre-exploitation evaluation, a distribution analysis study of fractures allowed to obtain an evaluation-based fractures index for the bench of the case study.